Correction: Hassanabadi et al. Hydraulic Characterization of Ceramic Foam Filters Used in Aluminum Filtration. Materials 2023, 16, 2805.

In the original publication [...].

Hydraulic Characterization of Ceramic Foam Filters Used in Aluminum Filtration.

Ceramic Foam Filters (CFF) are frequently used during the filtration of aluminum (Al) melts to produce high-quality products. In the present study, the physical and hydraulic characteristics of alumina (Al2O3)-based CFF from three different suppliers (A, B and C) have been thoroughly investigated. The filters' porosity and pore diameter, i.e., Window and Cell Feret diameters, were measured and the permeability of the different filters calculated based on pressure drop experiments. The comparison of the classification systems of CFF, i.e., Grade and PPI (Pore Per Inch) numbers, using statistical analysis of permeability and Window Feret diameter showed significant variations between the morphological and hydraulic properties of some CFFs of identical Grade and PPI numbers. Moreover, the Fanning friction factor was plotted as a function of interstitial Reynolds numbers (Rei), and laminar, transient, and turbulent flow regimes were identified. The relationship between the Fanning friction factor and the interstitial Reynolds numbers of all the filter samples investigated was processed using regression analysis, and a model equation developed to calculate the pressure drop over the CFF using the Window Feret diameter. The correlation between the experimental pressure drop values and the derived model equation indicates that empirical expressions for calculating the pressure drop over CFFs should be derived based on experimental measurements carried out at the velocity range of the application of the CFF, which is about 10 mm·s-1 for aluminum filtration.

Study and Modelling of Fluid Flow in Ceramic Foam Filters.

To investigate the fluid flow characteristics of conventional Ceramic Foam Filters (CFFs) of grades 30 and 50, a 2D macro-scale geometry was generated by converting pixel grid images of the filters into vector format images. The flow behaviour through the filter channels was then numerically modelled using the Stocks equation within the Creeping Flow interface of COMSOL Multiphysics®. Through modelling, the average interstitial velocity was estimated and found to be higher than the corresponding value obtained from the Dupuit-Forchheimer equation. The discrepancy obtained suggested that the flow behaviour within the filter channels differed from that based on the simplified assumptions of the equation. The porosity and permeability of the CFFs were evaluated during the post-processing stage using surface integration and user-defined equations. The experimentally determined porosity closely matched the values obtained from the simulation model, demonstrating the reliability of the numerical approach. However, the permeability values from the simulation of CFFs of grades 30 and 50 were higher than those obtained experimentally. This discrepancy can be attributed to the larger channels in the generated geometrical pattern compared to the original CFF structure. The present findings highlight the effectiveness of the proposed methodology in developing a representative macro-scale geometry for CFFs and in simulating fluid flow behaviour.

Quality of Cancer Care in Tanzania as Experienced by Patients: A Qualitative Study.

Introduction: Cancer is a disease of public importance in Tanzania. Considering a limited health care system with few cancer centers and low health literacy in general, people are diagnosed at late stage and face difficulties in accessing care for their cancer. All these challenges affect the caring situation for the nurses who meet the patients at the cancer care centers. Objective: This study aimed to explore the journey of cancer care experienced by patients with cancer.Research questions:How do patients experience the quality of care at the cancer care centers?How do patients experience the family's and the community's role? Methods: Semi-structured qualitative interviews were carried out with 15 patients treated for colorectal-, breast-, or prostate cancer in three cancer care centers in Tanzania. A purposive sampling was used. Qualitative content analysis according to Graneheim and Lundman was employed. Results: Three main themes and six sub-themes emerged. The main themes were e xperiences of cancer care services, the role of the family, community challenges and cancer care. The sub-themes were communication, resource allocation at the cancer care centers, fmily's denial, family challenges, limitations of primary care and misconceptions, and accessibility of cancer service and the health care system. The findings show that patients experienced incapacitated health care facilities for cancer care, misconceptions in the community and challenges for the families. Conclusions: The quality of cancer care in Tanzania needs to be improved, patients face challenges in all levels of health care facilities, including families, and the community at large. The distance to oncology care, economic hardship, and lack of knowledge in the community including families, lead to late diagnosis and suffering for the patients. There is a great need for education regarding cancer within healthcare, as well as in the community, to change the situation for patients with cancer.

"Caring for Breast Cancer Patients Is a Work That Brings Sorrow": A Qualitative Interview Study with Nurses in Tanzania.

Introduction: Breast cancer is increasing in sub-Saharan Africa (SSA), and most women are diagnosed at a late stage. This leads to increased suffering for the patients and challenging care situations for nurses. Limited resources in healthcare, lack of oncology training, and low health literacy in society result in even more demanding situations for nurses. Objective: The objective was to explore nurses' experiences of caring women for with breast cancer in Tanzania. Methods: The study employed a descriptive qualitative design. Fifteen nurses, working in oncology units in three major hospitals in Tanzania were interviewed using a semistructured interview guide. The participants had a minimum of 6 months experience of caring for breast cancer patients. Purposive sampling was used. Data were analyzed by qualitative content analysis. Results: Two main themes emerged: Challenges in caring for breast cancer patients and Nurses' psychological distress. The late diagnosis was very challenging for the nurses. Low health literacy regarding breast cancer disease and treatment, patients' financial difficulties, minimal oncology nursing education, and technology in healthcare systems were also major challenges. The nurses experienced psychological distress, lost hope, and faced ethical dilemmas while providing cancer care. Conclusion: The findings of this study conclude that nurses face emotional distress and ethical dilemmas while caring for patients with breast cancer. Late diagnosis, lack of infrastructure and resources, and low health literacy among patients, family, and healthcare providers have a great impact on the stress that the nurses experience.

Cross-Cultural Adaptation and Psychometric Properties of the Swahili Version of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-BR45 among Breast Cancer Patients in Tanzania.

Breast cancer is the most frequent cancer in women in Africa and contributes to premature death and poor quality of life. This study aimed to determine the validity, reliability, and psychometric properties of the Swahili version of EORTC QLQ-BR45 among women with breast cancer in Tanzania. A cross-sectional study design with non-probability convenience sampling was employed. Data were collected in two tertiary hospitals and one national cancer institute; 414 participants completed the EORTC-QLQ-C-30 and EORTC-QLQ-BR45. The reliability of QLQ-BR45 was measured using Cronbach's alpha and McDonald's Omega coefficients. The factor structure of EORTC QLQ-BR45 was assessed using confirmatory factor analysis. The internal consistencies for the five dimensions were all above 0.7 indicating satisfaction, except for systemic therapy side effects with a marginal value of 0.594 and significant correlations between the dimensions of QLQ-C30 and BR45. The final model fit well to the data, with the comparative fit index = 0.953, Tucker-Lewis index = 0.947, root mean square error of approximation = 0.041 (90% CI: 0.035, 0.046), and standardized root mean square residual = 0.072. In conclusion, the QLQ BR45 Swahili version displayed good reliability, validity, and psychometric properties and can be used in Swahili-speaking Sub-Saharan countries.

Quality Of Life in Children With Home Mechanical Ventilation - A Scoping Review.

Introduction: Home mechanical ventilation is an established method to support children suffering from chronic respiratory insufficiency, still more research is needed regarding mechanically ventilated children's and adolescents' quality of life (QoL). Therefore, the aim of this scoping review was to explore research regarding QoL and lived experience of children and adolescents with home mechanical ventilation. Methods: A scoping review with systematic searches for research studies published between year 2000-2020 was performed in Cinahl, Medline, and PubMed. Studies that met the inclusion criteria were quality assessed and a thematic analysis was performed. Results: In total, ten articles were quality assessed and included in the results. Four themes emerged: Children's self-reported QoL, Parents' perception and parent-proxy report, Differences between the child's and parent's perception, and challenges in daily life. Children with home mechanical ventilation reported a lower QoL than healthy children and children with other chronic diseases. Generally, parents rate their child's QoL lower than the children themselves. Conclusion: This is the first literature review focusing on HMV in the paediatric population. It is clear that HMV does not only affect the treated child or adolescent but also the whole family. It is important to regularly measure and evaluate QoL in children and adolescents with HMV to provide person-centered care. More research is needed to improve these children's and adolescents' QoL.

Probing heat generation during tensile plastic deformation of a bulk metallic glass at cryogenic temperature.

Despite significant research efforts, the deformation and failure mechanisms of metallic glasses remain not well understood. In the absence of periodic structure, these materials typically deform in highly localized, thin shear bands at ambient and low temperatures. This process usually leads to an abrupt fracture, hindering their wider use in structural applications. The dynamics and temperature effects on the formation and operation of those shear bands have been the focus of long-standing debate. Here, we use a new experimental approach based on localized boiling of liquid nitrogen by the heat generated in the shear bands to monitor the tensile plastic deformation of a bulk metallic glass submerged in a cryogenic bath. With the "nitrogen bubbles heat sensor", we could capture the heat dissipation along the primary shear banding plane and follow the dynamics of the shear band operation. The observation of nitrogen boiling on the surface of the deforming metallic glass gives direct evidence of temperature increase in the shear bands, even at cryogenic temperatures. An acceleration in bubble nucleation towards the end of the apparent plastic deformation suggests a change from steady-state to runaway shear and premonitions the fracture, allowing us to resolve the sequence of deformation and failure events.

Clinical use and material wear of polymeric tracheostomy tubes.

OBJECTIVES: The objectives were to compare the duration of use of polymeric tracheostomy tubes, i.e., silicone (Si), polyvinyl chloride (PVC), and polyurethane (PU), and to determine whether surface changes in the materials could be observed after 30 days of patient use. METHODS: Data were collected from patient and technical records for all tracheostomized patients attending the National Respiratory Center in Sweden. In the surface study, 19 patients with long-term tracheostomy were included: six with Bivona TTS Si tubes, eight with Shiley PVC tubes, and five with Trachoe Twist PU tubes. All tubes were exposed in the trachea for 30 days before being analyzed by scanning electron microscopy (SEM) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). New tubes and tubes exposed in phosphate-buffered saline were used as reference. RESULTS: Si tubes are used for longer periods of time than those made of PVC (P<.0001) and PU (P=.021). In general, all polymeric tubes were used longer than the recommended 30-day period. Eighteen of the 19 tubes exposed in patients demonstrated, in one or more areas of the tube, evident surface changes. The morphologic changes identified by SEM correlate well with the results obtained by ATR-FTIR. CONCLUSIONS: Si tracheostomy tubes are in general used longer than those made of PVC and PU. Most of the tubes exposed in the trachea for 30 days suffered evident surface changes, with degradation of the polymeric chains as a result.

Tribocorrosion studies of metallic biomaterials: The effect of plasma nitriding and DLC surface modifications.

The medical grade pure titanium, stainless steel and CoCrMo alloy have been utilized as biomaterials for load-bearing orthopedic prosthesis. The conventional surgery metals suffer from a combined effect of wear and corrosion once they are implanted, which may significantly accelerate the material degradation process. In this work, the tribocorrosion performance of the metallic biomaterials with different surface modifications was studied in the simulated body fluid for the purpose of investigating the effect of the surface treatments on the tribocorrosion performance and eventually finding the most suitable implantation materials. The metals were subjected to surface modifications by plasma nitriding in different treatment temperatures or physical vapor deposition (PVD) to produce diamond-like carbon (DLC) coating, respectively. The dry wear and tribocorrosion properties of the samples were evaluated by using a reciprocating ball-on-disc tribometer equipped with an electrochemical cell. Prior to the tribocorrosion tests, their electrochemical behavior was measured by the potentiodynamic polarization in phosphate buffer saline (PBS) solution at room temperature. Both stainless steel and CoCrMo after low temperature nitriding kept their passive nature by forming an expanded austenite phase. The DLC coated samples presented the low anodic corrosion current due to the chemical inertness of the carbon layer. During the tribocorrosion tests at open circuit potential, the untreated and low temperature nitrided samples exhibited significant potential drop towards the cathodic direction, which was a result of the worn out of the passive film. Galvanic coupling was established between the depassivated (worn) area and the still passive (unworn) area, making the materials suffered from wear-accelerated corrosion. The DLC coating performed as a solid lubricant in both dry wear and tribocorrosion tests, and the resulting wear after the tests was almost negligible.

Degradation of Zr-based bulk metallic glasses used in load-bearing implants: A tribocorrosion appraisal.

Owing to the amorphous structure, Bulk Metallic Glasses (BMGs) have been demonstrating attractive properties for potential biomedical applications. In the present work, the degradation mechanisms of Zr-based BMGs with nominal compositions Zr55Cu30Ni5Al10 and Zr65Cu18Ni7Al10 as potential load-bearing implant material were investigated in a tribocorrosion environment. The composition-dependent micro-mechanical and tribological properties of the two BMGs were evaluated prior to the tribocorrosion tests. The sample Zr65-BMG with a higher Zr content exhibited increased plasticity but relatively reduced wear resistance during the ball-on-disc tests. Both BMGs experienced abrasive wear after the dry wear test under the load of 2N. The cross-sectional subsurface structure of the wear track was examined by Focused Ion Beam (FIB). The electrochemical properties of the BMGs in simulated body fluid were evaluated by means of potentiodynamic polarization and X-ray Photoelectron Spectroscopy (XPS). The spontaneous passivation of Zr-based BMGs in Phosphate Buffer Saline solution was mainly attributed to the highly concentrated zirconium cation (Zr(4+)) in the passive film. The tribocorrosion performance of the BMGs was investigated using a reciprocating tribometer equipped with an electrochemical cell. The more passive nature of the Zr65-BMG had consequently a negative influence on its tribocorrosion resistance, which induced the wear-accelerated corrosion and eventually speeded-up the degradation process. It has been revealed the galvanic coupling was established between the depassivated wear track and the surrounding passive area, which is the main degradation mechanism for the passive Zr65-BMG subjected to the tribocorrosion environment.

Material wear of polymeric tracheostomy tubes: a six-month study.

OBJECTIVES: The objectives were to study long-term material wear of tracheostomy tubes made of silicone (Si), polyvinyl chloride (PVC), and polyurethane (PU) after 3 and 6 months of clinical use. STUDY DESIGN: The study has a prospective and comparative design. METHODS: Nineteen patients with long-term tracheostomy, attending the National Respiratory Center in Sweden, were included, n = 6 with Si tubes, n = 8 with PVC tubes, and n = 5 with PU tubes. The tubes were exposed to the local environment in the trachea for 3 and 6 months and analyzed by scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and differential scanning calorimetry. RESULTS: All tubes revealed severe surface changes. No significant differences were established after 3 or 6 months of exposure between the various materials. The changes had progressed significantly after this period, compared to previously reported changes after 30 days of exposure. The results from all analyzing techniques correlated well. CONCLUSIONS: All tubes, exposed in the trachea for 3-6 months, revealed major degradation and changes in the surface of the material. Polymeric tracheostomy tubes should be changed before the end of 3 months of clinical use.